System for dispensing fluids

ABSTRACT

An air-operated system for blending and dispensing fluids, particularly suited for use in blending and dispensing paint thinners and the like as they are employed in automotive paint shops. The system is characterized by a compartmented reservoir containing a plurality of types of fluids to be blended and dispensed; a manipulatable valve for successively dispensing charges of blended fluid; and an air-operated siphon pump coupled with both the reservoir and the valve for successively discharging charges of fluid drawn from the reservoir in response to manipulations of the valve.

United States Patent 1191 Sjostrand 1 Apr. 10, 1973 1 SYSTEM FORDISPENSING FLUIDS [76] Inventor: Gerald D. Sjostrand, 5440 East LansingWay, Fresno, Calif. 93727 22 Filed: Mar. 3, 1971 21 Appl.No.: 120,486

[52] US. Cl. ..222/145, 222/266, 222/387,

, 137/596.12 51 1111.0. ..B67d 5/60 58 FieldofSearch ..'...222/55, 387,389,

[56] References Cited UNITED STATES PATENTS 484,383 10/1892 Weatherhead..222/334 9/1965 Trumbull et al ..222l334 X 2,881,959 4/1959 Bitzer..222/334 Primary Examiner-Robert B. Reeves Assistant Examiner-James M.Slattery Attorne'y-Huebner & Worrel ABSTRACT An air-operated system forblending and dispensing fluids, particularly suited for use in blendingand dispensing paint thinners and the like as they are employed inautomotive paint shops. The system is characterized by a compartmentedreservoir containing a plurality of types of fluids to be blended anddispensed; a manipulatable valve for successively dispensing charges ofblended fluid; and an airoperated siphon pump coupled with both thereservoir and the valvefor successively discharging charges of fluiddrawn from the reservoir in response to manipulations of the valve.

3 Claim, 8 Drawing Figures PATENTEDAPRIOW 3,726,439

SHEET 1 UF 3 GERALD D. SJOSTRAND /N VE N TOP MW Kyla! PATENTEDAPRIUIQH 3726,439

SHEET 3 [IF 3 THINNER THINNER MRI/5 I50 AIR 46 36 44 a /54 M4 /60 mTHINNER 53 [5 AIR GERALD 0. saosmA/vo I 6. 051 INVENTOP MwrM A 7TORNEKS' SYSTEM FOR DISPENSING FLUIDS BACKGROUND OF THE INVENTION tions.

The prior art is replete with dispensing systems for use in deliveringfluids, under pressure. Among such systems are those currently employedin delivering paints and paint thinners to pots and tanks, of varioustypes, employed in feeding pneumatically-operated paint guns duringspray painting operations.

For reasons well understood by those versed in operations conducted inautomotive paint shops, it often is desirable to blend various types ofpaint thinners.

A technique often employed in blending paints, thinners and the likesimply involves opening a drum of selected materials to be blended andpouring selected quantities into pots or tanks to achieve a desiredblend. Of course, in addition to the inherent attendant fire hazardsthus created, such mixing techniques frequently result in substantialloss of the materials due to spillage and evaporative losses.Furthermore, the volatile nature of these materials normallynecessitates a use of storage space remote from areas of use thusintroducing an undesirable time-loss factor in painting operations.

Mixing valves have successfully been employed in blending thinner s foruse in paint shops and the like. One such mixing valve is provided witha plurality of inlet ports operatively coupled with selected sources ofmaterialsto be blended in proportions determined by the setting of thevalve. However, in delivering thinners from their sources to the mixingvalve, difficulty is, in some instances, encountered in avoiding certainhazards which normally can be expected to arise when delivering highlyvolatile materials under elevated pressures derived from a pneumaticsystem. For example, atomized thinner is extremely hazardous, hence, airmust be precluded from the delivery system, particularly where thesystem is pressurized system. Further, and for similar reasons, it isdesirable that the pressure of gas within the reservoir be maintained atatmospheric, in order to avoid fracturing the system and developing acombustible spray.

OBJECTS AND SUMMARY OF THE INVENTION It, therefore, is an object of theinstant invention to provide a practical and safe fluid dispensingsystem for use in dispensing volatile fluids.

It is another object to provide an improved, selectively operable systemfor dispensing volatile fluids in charges of predetermined quantities.

It is another object to provide an improved system for dispensingblended volatile fluids in successive charges.

It is another object to provide an improved fluid dispensing system foruse in blending and dispensing a plurality of types of paint thinnerswith an attendant absence of handling losses.

It is another object to provide a system for pumping, blending anddispensing paint thinners and reducers of types commonly employed inautomotive paint shops.

It is another object to provide an improved, economic and safe fluidblending and dispensing system particularly suited for use in dispensingblended charges of multiple types of thinners commonly employed in paintshops for automobiles, without subjecting users to the hazardous effectsof an over-abundance of vapors of the thinners.

These and other disadvantages are overcome through the dispensing systemof the instant invention which, as a practical matter, is a fluidactuated system which serves to dispense single charges of blended fluidfrom a manipulatable valve coupled with a plurality of single-chargesiphon pumps communicating with appropriately vented reservoircompartments containing therein thinners to be blended and dispensed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of thefluid blending and dispensing system of the instant invention.

FIG. 2 is a sectioned elevational view of a charged unit of a siphonpump, of the type shown in FIG. 1, with its diaphragm being fully seatedagainst one side of the shell of the unit.

FIG. 3 is an end view of a mixing valve depicted in FIG. 1.

FIG. 4 is a partially sectioned elevational view of a mixing valve ofthe type shown in FIG. 3, illustrating an inoperative position for thevalve components.

FIG. 5 is a fragmented, partially sectioned view of the valve shown inFIG. 4, illustrating an operative position for the valve components asthe system is rendered operative for dispensing a charge of fluid.

FIG. 6 is a sectioned view taken generally along line 6-6 of FIG. 4.

FIG. 7 is a perspective view of the check-valve employed in venting thedrums shown in FIG. 1.

FIG. 8 is an enlarged, fragmentary view of material employed in thediaphragm shown'in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingswherein like reference characters designate like or corresponding partsthroughout the several views, there is illustrated in'FIG. l a systemwhich embodies the principles of the instant invention.

Briefly, the system, as illustrated, includes a mixing valve, generallydesignated 10, coupled with a compartmented reservoir, generallydesignated 12, and a siphon pump, generally designated 14 and includinga plurality of units 15. A control system, generally designated 16, iscoupled with the mixing valve 10 and pump 14 in a manner such that thepump is caused to respond to an opening of the mixing valve and delivercharges of thinner, previously extracted, from multiple compartments ofthe compartmented reservoir 12.

Of course, it is to be understood that the compartmented reservoir 12 isof any suitable configuration so long as its compartments are capable ofconfining therein selected types and quantities of thinner to. beblended at the mixing valve 12. As illustrated in FIG. 1, thecompartmented reservoir 12 includes a pair of drums 18 within whichthinner normally is delivered from a supplier, however, closedcompartments of any configuration can be employed equally as well.

While the system of the instant invention particularly is suited for usein dispensing blended charges of thinner, it should readily be apparentthat the system can be employed in dispensing fluids, both blended anduncut, of a general nature.

The mixing valve which is of a known design preferably includes a dial20 supported at the distal end by a rotatable shaft 22. This shaftsupports the dial 20 in a manner such that the dial can be reverselyrotated for altering the blending function of the valve 10.Additionally, a pivoted handle 24, supported at a pivotal coupling 25,is provided to be grasped by an operator for-purposes of accommodating amanipulation of the valve for discharging a blended charge of thinnerdelivered thereto. The fluid is delivered from the reservoir 12 througha plurality of delivery lines 26, in

response to an activation of the pump 14. Aluminum tubing serves quitesatisfactorily for this purpose.

As shown, the mixing valve 10 includes a housing 30 having formedtherein a pair of inlet ports 32, FIG. 6, which communicates with thedelivery lines 26 through suitable screw-threaded fittings 34. Thehousing 30 is provided with a bore which serves as a mixing chamber,designated 36. The chamber 36 terminates in a transverse end wall 37,having a planar surface, and communicates with both ports 32 throughsuitably formed conduits 38 and a metering chamber 40. The meteringchamber 40, in effect, is a slotted, transverse passageway extendingbetween the conduits 38.

varied for thus altering the relative flow rates of the thinners as theyare delivered through the conduits 38 to the mixing chamber 36.Additionally, by advancing and retracting the metering shaft 44,relative to the metering chamber 40 the position of the sealing head 48,relative to the surface of the end wall 37 of the mixing chamber 36, isvaried for thus metering the total flow of a blended thinner or otherfluid from the metering chamber 40 to the mixing chamber 36. Of course,in the event retraction of the metering shaft 44 is maximized, afluid-tight seal is established between the sealing head 48 and theadjacent surfaces of the mixing chamber 36, whereupon the valve isclosed.

Coaxially related to the mixing chamber 36 there is a bore 42 whichbisects the metering chamber and extends through the end wall 37 of themixing chamber 36. Within this bore there is seated a metering shaft 44which, in turn, includes a transversely directed recess 46 sodimensioned as to register with the metering chamber 40 for conveying tothe mixing chamber 36 fluids delivered thereto from either of the ports32 when the recess is in communication with the chamber 36. The meteringshaft 44 preferably is formed as an integral part of the shaft 22.Therefore, reciprocating axial displacement of the metering shaft 44 is,in operation, achieved by reciprocating the shaft 22.

About the metering shaft 44 there is provided an annular sealing head 48so configured as to seat on the wall 37 for sealing the metering chamber40. Preferably, a suitable O-ring 50 is provided to assure that asealing of the metering chamber 40, from the mixing chamber 36, iseffected when the shaft 44 is in its retracted position, as illustratedin FIG. 4, for thus interrupting communication between the mixingchamber 36 and the metering chamber 40. However, when the metering shaft44 is in its extended position, within the mixing chamber 36, the recess46 is in simultaneous communication with the metering chamber 40 and themixing chamber 36 so that fluid delivered from the ports 32 is affordedentry into the mixing chamber 36 through the recess 46.

While the valve components employed in mixing the thinners form nospecific part of the instant invention, it is to be understood thatblending, orproportionate mixing, of the thinners delivered from theports 32 to the mixing chamber 36, is varied simply by rotating the dial20 so as to impart rotation to the metering shaft 44 whereby the angularorientation of the recess 46 relative to the metering chamber 40 and theconduits 38 is As a practical matter, the metering shaft 44 continuouslyis urged toward its retracted position by a compression spring 52 seatedin a concentric relationship with the distal end of the shaft 44,designated 53, in the chamber 36. Thus the spring is arranged to actagainst the sealing head 48. This spring has a spring constant adequatefor maintaining a sealing relationship between the sealing head 48 andthe adjacent surface of the end wall 37 of the mixing chamber 36.

In order to advance the metering shaft 44 toward its extended position,there is provided between the shaft 22 and the metering shaft 44 anannular cam surface 54 which circumscribes a portion of the shaft 22 asit extends from the housing 30. A cam rider 56 is provided to extendfrom the distalend of the pivoted handle 24 into a position tocontinuously engage the cam surface 54. Consequently, as the handle 24is pivoted, about the pivotal coupling 25, the cam rider 56 acts againstthe cam surface 54 and axially advances the metering shaft 44 throughthe bore 42 for thus advancing the sealing head 48 out of engagementwith the adjacent surfaces of the mixing chamber 36.

In practice, the handle 24 is a spring-loaded handle and employs acompression spring 57 to urge the cam rider 56 into constant engatementwith the cam surface 54. Of course, the spring constant of the spring 57necessarily is inadequate for overcoming the effects of the spring 52.

As a practical matter, the thinners are delivered from the mixingchamber 36 downwardly through a dispensing conduit 58 of a tubularconfiguration. Preferably, the dispensing conduit is so dimensioned asto employ the effects of surface tension in order to preclude drippingof the thinners once the valve 10 has been closed through an appropriatemanipulation of the handle 24.

In view of the foregoing, it should readily be apparent that a blendingof fluids delivered through the delivery lines 26 readily is achievablesimply by manipulating the dial 20, for selectively positioning therecess 46, and the handle 24 for permitting the thinners to be deliveredthrough the metering chamber 40, into the mixing chamber 36, and hencethrough the dispensing conduit 58 into selected pots, tanks and thelike, not shown, commonly employed with so-called spray guns.

valve 64 seated in the drums bunghole and a transfer line 66 couplingthe valve 64 with one of the delivery lines 26 through a T-fitting 68.The fitting 68 is disposed above the level of the thinner within thereservoir 12 in order to preclude undesired siphoning in the event aleak is introduced into the delivery line 26.

In practice, each of the siphon tubes 62 of the siphon system 60 isformed of a flexible tubing and is coupled with a transfer line 66 at aball-check valve 64. The ball-check valves 64, in effect, are of anysuitable commercially available design. In practice, however, each ofthe ball-check valves 64 includes a spring-loaded ball 70, FIG. 7,supported out of sealing engagement with an appropriately formed ballseat 72 by a spring 74. The purpose of the ball 70 and spring 74 is toaccommodate a one-way passage of fluid from the drum 18 in a mannerconstant with that of known ball-check valves.

The housing of each of the ball-check valves 64 includes a plurality ofscrew threads 78 which permit the valve to be screw-threadingly receivedwithin the bunghole of a drum 18 so that the siphon tube 62 can besuspended therefrom into the drum. As a practical matter, each of thedrums 18 is vented through a suitable venting port 79 drilled throughthe housing of the ball-check valve 64 associated therewith in a mannersuch as to accommodate reversing flow of gases therethrough, whereby thethinners within the drums 18 continuously are maintained undersubstantially constant atmospheric pressure. Hence, as a thinner issiphoned from the drums 18 atmosphere is permitted to enter through theventing ports 79 and conversely, in the event elevated pressure developswithin the drums 18, the pressure is relieved through the venting ports79. Consequently, the thinners within the drums 18 are pressurized byatmospheric pressure.

In order to effect a siphoning of the thinners from the drums 18, eachof the drums is associated with one unit of the siphon pumps 14. This isachieved by coupling each of the T-fittings 68 to one of the units 15 ofthe pump 14 through a standpipe 80. The standpipe 80 is of a rigid steelconstruction and, in effect, serves as a two-way conduit for firsttransporting fluid siphoned from an associated drum 18 toward theassociated pump 14 and subsequently delivering the fluid through theT-fitting 68 to an associated delivery line 26.

As a practical matter, once the siphon system 60 is functioning in themanner intended, the last quantity of fluid siphoned from an associateddrum 18 is retained within the standpipe 80 and is first discharged intoa delivery line 26. Hence, it is not necessary that the thinner bedelivered through the standpipe 80 into the siphon pump 14. Of course, areverse flow of thinner into the associated drum 18 is precluded, as areverse flow in the standpipes 80 is effected, due to the action of theball-check valve 64.

As best illustrated in FIG. 2, each of the units 15 of the pump 14includes a housing 81 formed of two shellhalves 82 and 84. Theseshell-halves are mated to form an annular lip 86 circumscribing theperiphery of each of the housings 81. The shell-halves are unitedthrough a plurality of screw-threaded pins 88 which extend through aplurality of appropriately formed openings. Thus the shell-halvestogether serve to establish therewithin a pumping chamber 89.

It is to be understood, however, that clamped includes two outer layers92 of foamed, closed-cell polyethylene sandwiching therebetwe'en a clothfabric 94. The fabric 94 can, if so desired, be formed of a suitablesynthetic material which imparts tensile strength to the diaphragm.

As also is shown in FIG. 2, the diaphragm 90, in ef-- fect, serves todivide the pumping chamber 89 into two non-communicating, hermeticallysealed subchambers 96 and 98, each being of a variable dimension. Hence,the chambers 96 and 98 define variable volumes dictated by theinstantaneous position of the diaphragm 90, as the diaphragm is, inoperation, oppositely displaced within the pump chamber 89.

The subchamber 96 is coupled with the standpipe through an internallythreaded port 100, by means of a suitable screw-threaded fitting 102.Similarly, the subchamber 98 is coupled with the control system 16through an internally screw-threaded port 104 and a suitablescrew-threaded fitting 106 provided at the distal end of a pneumaticpressure line 107 and seated therein. Hence, fluid is delivered into thesubchamber 96 through the port 100, while an actuator fluid, preferablycompressed air, is delivered into the subchamber 98 through the port 104from the line 107. The fluids thus delivered into the pump chamber 89act in opposite directions against opposite faces of the diaphragm forrepositioning the diaphragm within the pumping chamber 89.

In order to assure a proper functioning of the pump 14, a compressionspring 108 is seated within the shellhalf 82, preferably in acylindrical cavity 110 stamped or otherwise formed therewithin incoaxial relationship with the port 100. At the opposite end of thespring 108 there is provided a disk-shaped pressure plate 112 whichserves to support the center portion of the diaphragm 90 in a planarconfiguration as the diaphragm is .reversely advanced through the pumpchamber 89. r

In operation, the actuator fluid delivered through the fitting 106enters the subchamber 98 and acts against the adjacent face of thediaphragm 90 for forcing the diaphragm to advance against the combinedreaction forces of fluid confined .within the subchamber 96 and thespring 108. Continued advancement of the diaphragm serves to eject thefluid from the subchamber 96 into the standpipe 80 through the fitting102. Of course, once the pressure thus established within the subchamber98 is released through the port 104, the spring 108 is effective foragain seating the diaphragm 90 in its initial position in the shell-half84 for thus siphoning thinner from the associated drum 18 into thestandpipe 80 and from the standpipe 80 into the subchamber 96. Thus theadvancement of the diaphragm under the influence of the spring 108achieves a siphoning effect through the system 60. It will beappreciated, of course, that so long as the mixing valve 10 is closed,fluid cannot be drawn within the delivery lines 26.

The actuator fluid delivered through the fitting 106 into the subchamber98 is acquired through the control system 16 from a source of compressedair 114 which serves as a source of actuator fluid. While the source ofcompressed air 114 can be a simple air-bottle, preferably the source isan outlet manifold of a compressed air system of the type-normally foundin an automotive paint shop. Should it be found desirable to do so, asuitable compressing apparatus can be employed for delivering air underpressure to the control system 16. Hence, it should be apparent that theparticular source .of actuator fluid employed is a matter of convenienceonly. I v

The control system 16 includes a pressure regulator unit, generallydesignated 116', which is interposed between the source of compressedair 114 and the pump 14 for purposes of controlling the pressure of theair delivered to the control system 16. The control system 16 also isprovided with a two-way valve 118 coupled with the output side of thepressure regulator unit 116, as best shown in FIGS. 4 and 5. As apractical matter, the two-way valve 118 is provided with a housing 120coupled with the housing 30 of the mixing valve through suitable screws122.

The housing 120 also is provided with a pair of axially spaced portsincluding an inlet port 124 and an out let port 126. The port 126communicates with each of the units of the pump 14, through thepneumatic,

pressure line 107. In practice, the line 107 is a bifurcated lineincluding a T-fitting, not designated, to cou ple each of thesubchambers 98 with the port 126. Within the port 126 there is seated afitting 130 for coupling the pneumatic pressure line 107 with the valve118, while a fitting 132 similarly is provided for coupling the valve118 with the pressure regulator unit 116 through a suitable stub-line,not designated.

The housing 120 is machined or otherwise provided with a bore 134, whichreceives therein a reciprocating shuttle plug 136, and a recess 138coaxially related to the borel34. The recess is of a diameter common tothat of the mixing chamber 36 but is of a toroidal configuration definedby a concentrically related tubular body 140. This body is, of course,coaxially related to the bore 134.

' It is important to note that when the housing 120 is united with thehousing 30, the recess 138 forms an end portion of, the mixing chamber36 and therefore is coaxially related to the sealing head 48.Accordingly, the recess serves to receive and support the opposite endof the compression spring 52. Hence, it should readily be apparentthat'the compression spring 52 is concentrically supported by thetubular body 140, as well as by the distal end 53 of the metering shaft44.

The body of the shuttle plug 136, not designated, is of a diameterapproximating the diameter of the bore 134 and is seated for axialreciprocation therein. A plurality of O-rings 142 serves to establish anhermetic seal about the periphery of the shuttle plug as it isreciprocated within the bore 134, between first and second positions.

As the shuttle plug 136 is caused to seat in the first position, theinlet port 124 is sealed from communication with the bore 134, andconsequently communication with the outlet port 126 is interrupted.However, as the shuttle plug 136 reversely is displaced to its secondposition, the ports 124 and 126 are caused to communicate through thebore 134. Hence, it is possible to achieve a sealing of the inlet port124, for thus interrupting a flow of air between the inlet and outletports, by seating the plug 136 in its first position and to open theinlet port to accommodate delivery of air to the outlet port by seatingthe plug in its second position wherein the port 124 is uncovered by theperiphery thereof.

As illustrated in FIG. 5 the bore 134 includes an annular shoulder 144against which the shuttle plug 136 is permitted to seat, as it is seatedin its first position, for

thus assuring a sealing of the inlet port 124. In order to seat the plug136 in its first position, a compression spring 146 is mounted withinthe bore 134 and supported .under compression by a suitable retainer148. Therefore, it should be apparent that the spring 146 acts againstthe shuttle plug 136 for continuously urging the shuttle plug into aseated disposition against the annular shoulder 144 so that the valve118 normally is closed.

Accordingly, it should be appreciated that the twoway valve 118 is anormally closed valve which is, in operation, opened for accommodating apassage of air under pressure to the pump 14 through the pneumaticpressure lines 107. 1

In order to achieve an opening of the two-way valve 118, there isprovided a push rod 150 which is seated for axial reciprocation withinthe tubular body 140. The rod 150 is extended from within the bore 134into engagement with the distal end 53 of the metering shaft 44 so thatas the metering shaft 44 is advanced into the mixing chamber 36, inresponse to a manipulation of the handle 24, the push rod 150 isadvanced into the bore 134. As a practical matter, the push rod 150 iscircumscribed by an O-ring seal which serves to hermetically seal themixing chamber 36.

interposed between one endof the shuttle plug 136 and, in engagementwith the adjacent end of the push rod 150, there is a spring-loaded ball154. This ball is adapted to seat on an annular shoulder 156concentrically formed within the end of the shuttle plug 136. Inpractice, the shoulder 156 circumscribes the base of a first recess 158coaxially related to the push rod 150 and coaxially is related to anadjacent spring-retaining recess 160. A compression spring 162 is seatedwithin the recess 160 and extended into a biasing engagement with theball 154 so that the ball is urged into a spaced relationship with theshoulder 156 of the recess 158. Preferably, the spring constant of thespring 162 is such that the spring 162 cannot overcome the applied forceof the spring 146.

Hence, it should readily be apparent that in order for the push rod 150to displace the plug in an axial direction, as it axially is displaced,the push rod must be advanced through a distance sufficient for causingthe spring 162 to collapse and the ball 154 to seat on the shoulder 156of the recess 158. However, once the ball is seated and motion of theshuttle plug 136 is continued, axial movement of the plug is initiatedfor thus unsealing the inlet port 124.

Accordingly, it is to be understood that as the handle 24 is displaced,for thus opening the mixing valve 10, the push rod 150 is caused to seatthe ball 154 on the shoulder 156 and displacement of the shuttle plug,against the applied force of the spring 146, is initiated so that theport 124 is caused to communicate with the port 126 through the bore134. Hence it can be appreciated that the pump 14 remains inactive untilsuch time as the mixing valve 10 has been opened and the shuttle plug136 responsively has been displaced by the push rod 150. Of course, asthe ports 124 and 126 are caused to communicate, passage of air underpressure from the source of compressed air 114 to the subchamber 98,through the valve 118, is accommodated. Hence, pressure is developed inthe subchamber 98. Continued passage of the air to the subchamberpressurizes the subchamber to an operative magnitude sufficient fordisplacing the diaphragm 90.

In order to relieve pressure thus established within the subchamber 98,the shuttle plug 136 and the retainer 148 are provided with coaxiallyrelated openings 164 and 166. The opening 164 is, in effect, an axialbore extending through the shuttle plug 136 into communication with therecess 160. Hence, so long as the ball 154 remains out ofsealingengagement with the shoulder 156, each of the subchambers 98 connectedwith the valve 118, through the bifurcated line 107, communicates withatmosphere. However, once the push rod 150 is advanced for displacingthe shuttle plug 136, the ball 154 is caused to seat and thus seal theopening 164 so that an elevated pressure can be established within thesubchambers 98. Accordingly, it should readily be apparent that thespring-loaded ball 154 and the opening 164 serve as a relief valve foraccommodating a simultaneous depressurization of the subchambers 98 ofthe units 15.

OPERATION lt'is believed that in view of the foregoing description, theoperation of the system will be readily understood and it will bebriefly reviewed at this point.

With the system assembled in the manner hereinbefore described, it isprepared by coupling the delivery lines 26 with the drums 18, locatedwithin the reservoir 12 and remotely separated from the mixing valve 10,and the system by coupling the valve 118 with the source of compressed.air 114. The mixing valve handle 24 can now be manipulated in a mannersuch as to prime the system and fill the delivery lines 26 with thinnerssiphoned from different drums 18.

Once the system is primed and the lines 26 have been filled, the systemof the instant invention is prepared for operation and can be employedfor blending the thinners derived from the drums 18. In order to achievea desired blending, the dial 20 is manipulated for rotating the meteringshaft 44 in a manner such that different flow rates are established bythe metering shaft 44 for the delivery of fluid from each of the lines26, through the ports 32 and the metering chamber 40 into the mixingchamber 36. Hence, the fluid can be dispensed as a predetermined blendfrom the dispensing conduit 58.

In order to impose a dispensing mode of operation on the valve 10, thehandle 24' is advanced against the spring 57 and in a direction suchthat thecam rider 56 acts against the cam surface 54 for axiallyadvancing the metering shaft 44. As the metering shaft 44 is advanced,the sealing head 48 is unseated with respect to the planar surface ofthe end wall 37 of the mixing chamber 36 thus permitting a flow of fluidto be established from the metering chamber 40 through the mixingchamber 36 to the dispensing conduit 58.

Continued motion of the handle 24 axially advances the push rod 150 forcausing the push rod to advance the spring-loaded ball 154 against theapplied force of the spring 162. Continued advancement of the push rodcauses the ball 154 to seat against the shoulder 156 of the shuttle plug136. As seating of the ball 1S4 occurs, the opening 164 is sealed.Continued advancement of the push rod 150, in response to motionimparted to the handle 24, causes the shuttle plug 136 to advance alongthe bore 134 for unsealing the inlet port 124, whereupon compressed airis delivered from the source 114 into the pneumatic pressure lines 107through which it is distributed to all of the subchambers 98,simultaneously, causing the subchambers 98 to expand against the appliedforces of the springs 108, as well as back pressures developed withinthe subchambers 96. As the subchambers 98 are expanded, thinners orother fluids, contained within subchambers 96 are formed through theports 100, the standpipes 80, the T- fittings 68, the delivery lines 26and the ports 32 and into the mixing chamber 36 of the valve 10, fromwhich the fluids are dispensed through the dispensing conduit 58.

Once the handle 24 is released, the springs 146, 162, 52 and 108 act toreverse the position of their associated system components for thuscausing the plug 136 to seal the inlet port 124, the ball 154 to unseatand the subchamber 98 to vent to atmosphere so that the subchambers 96are permitted to expand, under the influence of the springs 108, forsiphoning fluid from the associated drums 18, through the check-valve64, as the spring 52 drives the metering shaft 44 to a position whereinthe sealing head 48 closes the metering chamber 40. Reseating of themetering shaft thus reseals the mixing valve 10 and the system thus isprepared for another cycle of operation.

in view of the foregoing, it should readily be apparent that the systemof the instant invention provides a simple and practical solution to theproblem of delivering and blending volatile fluids, particularlythinners, to points of use within confined areas, such as automotivepaint shops and the like.

'Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the illustrative detailsdisclosed.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A system for dispensing fluid comprising:

A. a fluid circuit including a reservoir;

B. a manipulatable valve coupled with said circuit adapted to be openedfor discharging fluid delivered thereto from said reservoir;

C. an activatable pump coupled in said circuit in operative associationwith said valve and said reservoir for delivering fluid from thereservoir to the valve; and

D. control means for activating the pump in response to a manipulationof the valve, including:

1. means defining an hermetically sealed chamber including meansdefining therein a pressure port coupled with a source of fluid underpressure and a delivery port coupled with said pump,

2. a shuttle plug seated for axial reciprocation within saidhermetically sealed chamber for sealing said pressure port when seatedin a first position within the chamber and for opening said pressureport when seated in a second position axially displaced from said firstposition,

3. means defining a resealable vent in said shuttle plug for ventingsaid chamber to atmosphere when said shuttle plug is in said firstposition and for sealing said chamber to atmosphere when said plug is insaid second position,

4. biasing means continuously urging said shuttle plug in displacementtoward said first position, and

5. a push rod supported for axial reciprocation and extended betweensaid sealed chamber and said valve in coaxial alignment with saidshuttle plug for forcing said plug in displacement toward its secondposition, against said biasing means, in response to an opening of saidvalve, and for accommodating a displacement of said shuttle plug to itsfirst position in response to a closing of said valve.

2. The system of claim .1 wherein the vent includes:

A. means defining an axial bore extended through said shuttle plug;

B. means defining within said shuttle plug a first retainer chambercoaxially related to said bore;

C. means defining a second retainer chamber communicating with saidfirst retainer chamber and said hermetically sealed chamber, includingmeans defining an annular ball-seat circumscribing' one end ofsaidsecond retainer chamber adjacent to said hermetically sealedchamber;

D. a compression spring seated in said first retainer chamber andaxially extended into said second retainer chamber; and

E. a ball seated in said second retainer chamber in engagement withsaidpush rod and said compression spring, supported out of engagementwithsaid ball-seat by said'spring' andjpositionable againstplacementtoward its second position; A 3. A system for dispensingsuccessive charges of selectively'blended fluidscomprising:

C. a mixing valve including multiple intake ports,

each port communicating with a given siphon tube .45. said'ball-seat inresponse to axial advancementof said push rod as said shuttle plugisforced in disand a discharge port commonly communicating with all ofthe intake ports;

D. a one-way check valve interposed between each siphon tube and saidmixing valve;

E. a plurality of pumps, each pump having a chamber coupled with asiphon tube through a fixed orifice and means including a displaceablediaphragm dividing said chamber into firstand second adacentsubchambers, each having an instantaneous volume determined by theinstantaneous position of the diaphragm;

F. a compression spring seated in each of the first subchambers forcontinuously urging the diaphragm in displacement toward the adjacent Isecond subchamber;

G. a pneumatic conduit coupled with a source of compressed air andterminating in the second subchamber of each pump, whereby air underpressure simultaneously delivered from the source to each of said secondsubchambers, through said conduit, is caused to act against thecompression springseated in the adjacent first subchamber forsimultaneously moving said diaphragms in displacement toward saidadjacent first subchamber; and

H. a pneumatic valve interposed in said conduit and operatively coupledwith said mixing valve including valve means for accommodating asimultaneous delivery of air to the second subchamber of said pluralityof pumps, subsequent to an opening of said mixing valve, for thussimultaneously forcing a charge of fluid from said first subchambers,through the fixed orifices, and simultaneously to bleed delivered airfrom each of said second subchambers when the mixing valve is closed, sothat each compression spring is permitted to move one of the diaphragmstoward a second subchamber for thus drawing a charge of fluid from thereservoir, including: 1. means defining a pneumatic chamber of acylindrical configuration; 2. means defining within the chamber a pairof axially spaced ports; 3. a spring-loaded shuttle [plug seated in saidchamber axially displaceable 'between a first seal one of said ports anda second position through said chamber; 4. a compression springoperatively associated with said plug continuously urging the plugtoward said first position; and 5. means defining a check valveoperatively associated with said chamber including means for ventingsaid chamber when said shuttle plug is in said first position.

* l l 1 I! position wherein said plug serves to hermetically f. whereinsaid 'ports'are afforded communication

1. A system for dispensing fluid comprising: A. a fluid circuitincluding a reservoir; B. a manipulatable valve coupled with saidcircuit adapted to be opened for discharging fluid delivered theretofrom said reservoir; C. an activatable pump coupled in said circuit inoperative association with said valve and said reservoir for deliveringfluid from the reservoir to the valve; and D. control means foractivating the pump in response to a manipulation of the valve,including:
 1. means defining an hermetically sealed chamber includingmeans defining therein a pressure port coupled with a source of fluidunder pressure and a delivery port coupled with said pump,
 2. a shuttleplug seated for axial reciprocation within said hermetically sealedchamber for sealing said pressure port when seated in a first positionwithin the chamber and for opening said pressure port when seated in asecond position axially displaced from said first position,
 3. meansdefining a resealable vent in said shuttle plug for venting said chamberto atmosphere when said shuttle plug is in said first position and forsealing said chamber to atmosphere when said plug is in said secondposition,
 4. biasing means continuously urging said shuttle plug indisplacement toward said first position, and
 5. a push rod supported foraxial reciprocation and extended between said sealed chamber and saidvalve in coaxial alignment with said shuttle plug for forcing said plugin displacement toward its second position, against said biasing means,in response to an opening of said valve, and for accommodating adisplacement of said shuttle plug to its first position in response to aclosing of said valve.
 2. a shuttle plug seated for axial reciprocationwithin said hermetically sealed chamber for sealing said pressure portwhen seated in a first position within the chamber and for opening saidpressure port when seated in a second position axially displaced fromsaid first position,
 2. The system of claim 1 wherein the vent includes:A. means defining an axial bore extended through said shuttle plug; B.means defining within said shuttle plug a first retainer chambercoaxially related to said bore; C. means defining a second retainerchamber communicating with said first retainer chamber and saidhermetically sealed chamber, including means defining an annularball-seat circumscribing one end of said second retainer chamberadjacent to said hermetically sealed chamber; D. a compression springseated in said first retainer chamber and axially extended into saiDsecond retainer chamber; and E. a ball seated in said second retainerchamber in engagement with said push rod and said compression spring,supported out of engagement with said ball-seat by said spring andpositionable against said ball-seat in response to axial advancement ofsaid push rod as said shuttle plug is forced in displacement toward itssecond position.
 2. means defining within the chamber a pair of axiallyspaced ports;
 3. a spring-loaded shuttle plug seated in said chamberaxially displaceable between a first position wherein said plug servesto hermetically seal one of said ports and a second position whereinsaid ports are afforded communication through said chamber;
 3. meansdefining a resealable vent in said shuttle plug for venting said chamberto atmosphere when said shuttle plug is in said first position and forsealing said chamber to atmosphere when said plug is in said secondposition,
 3. A system for dispensing successive charges of selectivelyblended fluids comprising: A. a reservoir having a plurality ofcompartments vented to atmosphere, each compartment confining a selectedfluid under atmospheric pressure; B. a plurality of siphon tubes, eachoperatively disposed within a compartment of said reservoir; C. a mixingvalve including multiple intake ports, each port communicating with agiven siphon tube and a discharge port commonly communicating with allof the intake ports; D. a one-way check valve interposed between eachsiphon tube and said mixing valve; E. a plurality of pumps, each pumphaving a chamber coupled with a siphon tube through a fixed orifice andmeans including a displaceable diaphragm dividing said chamber intofirst and second adjacent subchambers, each having an instantaneousvolume determined by the instantaneous position of the diaphragm; F. acompression spring seated in each of the first subchambers forcontinuously urging the diaphragm in displacement toward the adjacentsecond subchamber; G. a pneumatic conduit coupled with a source ofcompressed air and terminating in the second subchamber of each pump,whereby air under pressure simultaneously delivered from the source toeach of said second subchambers, through said conduit, is caused to actagainst the compression spring seated in the adjacent first subchamberfor simultaneously moving said diaphragms in displacement toward saidadjacent first subchamber; and H. a pneumatic valve interposed in saidconduit and operatively coupled with said mixing valve including valvemeans for accommodating a simultaneous delivery of air to the secondsubchamber of said plurality of pumps, subsequent to an opening of saidmixing valve, for thus simultaneously forcing a charge of fluid fromsaid first subchambers, through the fixed orifices, and simultaneouslyto bleed delivered air from each of said second subchambers when themixing valve is closed, so that each compression spring is permitted tomove one of the diaphragms toward a second subchamber for thus drawing acharge of fluid from the reservoir, including:
 4. biasing meanscontinuously urging said shuttle plug in displacement toward said firstposition, and
 4. a compression spring operatively associated with saidplug continuously urging the plug toward said first position; and 5.means defining a check valve operatively associated with said chamberincluding means for venting said chamber when said shuttle plug is insaid first position.
 5. a push rod supported for axial reciprocation andextended between said sealed chamber and said valve in coaxial alignmentwith said shuttle plug for forcing said plug in displacement toward itssecond position, against said biasing means, in response to an openingof said valve, and for accommodating a displacement of said shuttle plugto its first position in response to a closing of said valve.